How to Repair a Door Lock in a House

The bulk of lock problems can be repaired with simple maintenance. Only after you have attempted some of these tips should you be tempted to call a professional locksmith. Fortunately, most of the tools and supplies necessary for repairing door locks are found in most homes.

Things You'll Need

• Screwdriver
• File
• WD-40
• Cleaning solvent

Instructions

1. Tighten the setscrew on the face in the edge of the door with a mortise lock. These screws are often hidden behind a false plate. Loosening these screws allows the cylinder to be unscrewed so that it can be removed. Use the key to turn the cylinder out for readjustment, and then retighten.

2. Fix the latch on a door lock by realigning the spindle. First remove the spindle and the setscrews for stripped threads. If either the spindle itself or the screws need to be replaced, go ahead and replace them. Center the spindle back into the shaft, and make sure the knobs are repositioned so that they fit snugly against the protective plate known as the escutcheon.

3. Realign the bolt and strike plate if the problem is that the key is difficult to turn when the door is closed, but easy when the door is open. The problem here is that the dead bolt rubs against the strike plate in the door frame. You may have to file the strike plate opening so that it is larger.

4. Remove the entire lock if the problem is that the right key has difficulty turning. Soak the parts of the lock in a cleaning solvent, and then scrub the surface with a toothbrush. Lubricate with WD-40. A key that is hard to turn is usually the result of a lock and latch that has gotten dirty. A thorough cleaning will save you the expense of buying a new lock.